Elevator safety device



March 141, 195G P. PAQUIN 2,5 72

ELEVATOR SAFETY DEVICE Filed Jan. 175, 1947 v 50 .29 9 gg 2 5i {9 x ////////////'f /////////////////////A 29 Q0 1 l lbmf/yfor Patented Mar. 14, 1950 UNITED STATES PATENT OFFICE ELEVATOR SAFETY DEVICE Patrick Paquin, Timrnins, Ontario, Canada Application January 13, 1347, Serial No. 721,818

6 Claims.

The present invention pertains to a novel elevator safety device having the purposes disclosed in my co-pending application Serial No. 609,225 filed August 6, 1945, now abandoned, and consisting of various improvements and modifications thereof.

The principal object of this invention, as in the earlier invention, is to provide simple and effective means of arresting the descent of a falling elevator due to a bro-ken cable or other cause. This object is accomplished generally by the use of a speed-actuated mechanism which throws gripping members or dogs into engagement with the rails, thereby bringing the elevator to a stop shortly after the uncontrolled descent has started.

In the accomplishment of this object, the elevator carries a rotatable shaft on which is mounted a wheel that rides in engagement with one of the rails. The shaft carries a loose clutch. member and a complementary slidable clutch element operated by a centrifugal governor. When the speed of the elevator becomes eXcessive, the governor throws the clutch element into engagement with the clutch member, and the latter operates the holding dogs. A one-way drive is provided between the wheel and the shaft so that the latter rotates only on the descending movement of the elevator.

The binding dogs are carried by shafts also journalled in bearings on the elevator. Levers extending laterally of these shafts carry a pair of nuts in which is mounted a reversely threaded screw. The aforementioned clutch member carries a sprocket wheel connected by means of a chain to another sprocket wheel on the screw. Thus, when the clutch is engaged, the screw is driven and the nuts are displaced on the screw. The latter movement turns the dog-carrying shafts by means of the levers, and the dogs are thus brought into binding engagement with the rails.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings in which:

Figure 1 is a bottom plan view of the mechanism, showing the elevator guide rails in section;

Figure 2 is a vertical elevation;

Figure 3 is a section on the line 3-3 of Figure 1; and

Figure 4 is a section on the line 4-4 of Figure 1.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

The elevator l shown in Figure 1 moves between a pair of vertical guide rails 2. The safety mechanism is carried by the elevator and includes a shaft 3 on which is slidably keyed a governor sleeve 4. The shaft also carries a fixed disk 5 and a slidable clutch element 6. The

latter is connected to the sleeve 4 by rods Iv passing through the disk 5. A disk 8 is formed on the sleeve 4 and is joined to the disk 5 by a number of fiat springs 9 carrying weights Ill.v A coil spring ll surrounds a portion of the shaft 2, having one end bearing against an enlarged.

end l2 of the sleeve 4 and the other end engaged by a pair of adjustable nuts l3 on the shaft. whereby to hold the clutch element 6 in a retracted position.

On the shaft is also mounted a loose wheel or tire l4 riding along one of the rails 2. The member l4 carries a series of pawls l5 adapted to engage and drive a ratchet l6 fixed on the shaft 3, as the elevator descends. In the ascending direction, the pawls merely ride over the ratchet l6, and the mechanism associated with the shaft 3 is then inoperative.

The shaft 3 carries another loose sleeve I1 formed with a complementary clutch element 18 opposite the member 6 and normally spaced;

therefrom.

Suitable bearings l9 carried by the elevator 1 support a pair of shafts 20 lying transversely on the shaft 3. Each shaft 20 is interrupted the two wheels are joined by a sprocket chain- The shaft 3 may be held in a bearing 28 2i. as shown in Figure 2.

The shafts 20 carry dogs 29 adapted to bind against the sides of the rails 2 under the conditions presently to be described. Each dog has a handle or lever 30 by means of which it may be taken out of engagement with the rail. The two shafts 20 are preferably geared together at 3! for simultaneous operation.

In the operation of the device, the descending elevator rotates the shaft 3 and the governor sleeve 4. In case of excessive speed, as when a cable breaks, the speed of the sleeve 4 is greatly increased, and the weights ID are thus thrown outward with suflicient force to cause the sleeve to slide against the pressure of the coil spring II. The clutch member 6 is thereby brought into engagement with the clutch member l8, driving the sprocket 26, the chain 21 and the sprocket 25 which in turn rotates the screw 24.

The rotation of the reversely threaded screw 24 draws thenuts 23 inward, causing the levers to turn the shafts 20. The ends of the links attached to the nuts swing in an arc, and the vertical component of the are is taken up by a lifting movement of the screw 24, so that no other paired, the dogs are released from-thrails by hammering on the levers 30. The geared connection 3| between the shafts 2!! causes the dogs to actin unison.

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various'alterations in the details of tonstruction'maybe 'made Without departing from the 'scop'e"of theinventio'n as indicated by the-append d claims.

" What I"clai1'nas" my "invention is: I

1." In an elevator safety device, an elevator moving between guide rai1s,'a rotatable "shaft carried by" Saidelevator, a rail engaging wheel mounted thereon-a loose clutchmem'ber on said shaft, a centrifugal governor on said shaft,- a complementary clutch element operable by said governor to engage said clutch member, a pair of shafts transverse of the first shaft "and'jour nall'ed =on said -'elev'a'itor, levers extending "outwardly from said'pair of" shafts, nut carried by said" levers, a revers'elyth'rea'ded screw mounted said nuts, a driving connection from said clutch member to said screw, and dogs mounted on"said '-pa'ir of shafts and adapted to bind .on said-rails. a

2. In an elevator 'safety device, an elevator movingbetwee'n guide rails, a rotatable shaft carried by said elevator, a rail-engaging wheel mounted tnre'on, a "loose clutch member O'Il'Said shaft, a centrifugal governor on said shaft, a complementary cluteh'element operable by said governor to engage said clutch member, a pair of shafts-transverse 'of'th'e first shaft and journalled" on'*s'aid elevator, levers extending outwardly froin' s'aid pair of 'siiafts, nuts-carried by said levers, a reverselythreaded screw mounted,

in *said'nut's', a driving connection from said c1iitcli' member to said screw, and dogs mounted on s'aid' pair of shafts "and adapted to bind on s'aid 'rai ls, the shafts of said pair being geared together.

3. In an elevator safety device, an elevator movingbetween guide rails, a rotatable shaft'ca'rr'ied sai'd elevator, a rail-engaging wheel mounted thereon, -a loose clutchmember on said shaft, a centrifugal governor on said shaft, a complementary clutch'element operable by said governor to engage said clutch member,'a pair of shafts transverse of the first shaft and journalled on said elevator, levers "extending outwardly from said pair of shafts, nuts carried by:

from said clutch member to said screw, and dogs mounted on said pair of shafts and adapted to bind on said rails.

4. In an elevator safety device, an elevator moving between guide rails, a rotatable shaft carried by said elevator, a rail-engaging wheel mounted thereon, a loose clutch member on said shaft, a centrifugal governor on said shaft, a complementary clutch element operable by said governorto engage said clutch member, a pair of shafts transverse of the first shaft and journalled on said elevator, levers extending outwardly from said pair of shafts, nuts carried by said "levers, a reversel y threaded screw mounted in said nuts, said nuts constitutingthe sole support for said screw, a driving connec tion from-said clutch' member to said screw, and

dogs mounted on said pair of shafts and adapted governor to engage s'a-id clutch membenapair of shafts transverse of the -first shaft and jour nalled on said elevator, levers attending out wardly-froin' said pair of shafts, nuts carried by said levers, a 'rever'sely threaded screw mounted-insaid nuts, said nutsconstituting the i sale-support rorsaid'screw, a sprocket and chain connection from said clutch member to said screw, and dogs mounted on said pair of shafts and adapted tobi nd 'on said rails.

SJ In an elevator safety device, an elevator moving between guide rails, :a rotatable shaft car ried by said elevator, a"rail-en'gag'ing wheelmounted thereon, a one-Way drive between said wheel and shaft and operable inthe descending direction of the elevator-,- a loose clutch member on said shaft, a centrifugal governor on said shaft, a complementary clutch element operable by said go'x' ernor to engage said clutchmerribe'i, a'pa'ir of shaftstransvers'e "of the first'sha'ft and journalled on said elevatorglev'ers extending out \vardly from said pair "of shafts, nuts carried by said levers, a reversely threaded screw" mounted in "said nuts, a driving connection from PATRICK PAQUlN,

bio-"references cited; 

